Curious_George

I don't know all the details about your autoformer fiasco, but it sounds like another vendor is in order...

Here is an interesting paper on motor run caps. CDE-Motor-Run-Capacitors.pdf

The physical construction is not the same (not just shape and look), which means the characteristics cannot be identical. I believe all the "motor run" type caps nowadays are polypropylene, but I could be mistaken.

This may be suicide but here goes... The video posted documents replacing the old oil type capacitors with new JEM metallized film caps in a LaScala. Ok, no big deal. But here is the rub... we all know that the old oil type caps have different specifications (i.e.; ESR, DA, DF, moisture absorbtion, etc) than metallized film. So how can a metallized film be a direct replacement for an oil type and still be "in spec"? Logic would dictate that the "original sound" of the speaker will be different with the metallized film cap.

Some of those plots Bob C. use to post look like they were from 1935.

I think I can see you...

I was born in Pensacola, yep, Navy brat.

Is that still Florida? Ha ha, just joking. I'm in north central North Carolina, about 10 minutes south of the VA/NC border. Very rural, but beautiful here and there are actually 4 seasons.

On my loudspeakers that are not Klipsch, I made Zobel Networks to ensure the impedance is flat for my tube amps. Dayton VATS software is great for this and affordable. https://www.parts-express.com/Dayton-Audio-DATS-V3-Computer-Based-Audio-Component-Test-System-390-807

Where is "big bend"?

When I lived in Florida (Orlando) it meant 3 more months of humidity, which is the main reason I left. 49 years of it was enough.

I always wondered what the word "Seth" had to do with the amp. Any info?

Anybody doing anything special this weekend? Fall is just around the corner (hopefully). This weekend is the "last hoorah" for the camping season. We have a local band coming in Saturday. Business will start winding down until we close for the winter 12/1/22.

I don't know who actually came up with the idea of using the "swaping resistor", but I like how it flattens the impedance curve. Some speaker designers (not many) actually aim for a flat impedance curve as part of their crossover network design, many do not. Since I am a "tinkerer", I love being able to switch auto-former taps and/or drivers and not worry about changing a capacitor.

https://audiofederation.com/hifiing/2006/VTV2006/500/index.htm I'd be surprised if any of this equipment is still available or manufactured. I was too lazy to Google each brand, but I know for a fact, a lot of the brands are defunct.

Cornish Hen?

The Heresy will now fullfil it's namesake by modifying it. It is not recommended to stuff it by some, as a bit of efficiency will be lost and that was not the way it was designed. However, I would stuff it even without the port mod. You can use poly-fill pillow stuffing, or eggcrate foam from a place like Jo-Anns or maybe Walmart. An eggcrate mattress topper will work too. If you use poly-fill, lightly stuff the enclosure. If you use egg crate, line the sidewalls, backwall and top and bottom walls.

Too bad Rod Serling can't make a cameo... we would officially be in the Twilight Zone.

Would you expect anything less?

“Contradictions do not exist. Whenever you think that you are facing a contradiction, check your premises. You will find that one of them is wrong.” ~ Ayn Rand A premise is "facts and/or data". Not all data is accurate and not all facts are facts. I know we are talking about capacitor data in this case and it is hard to dispute manufacturer data such this. But a blanket statement like "facts & data are not biased" is not necessarily accurate.

I agree.

"Simply studying something fundamentally changes that thing... inserting a bias" Simply studying something, fundamentally changes (AKA - the way you perceive it), that thing. Inserting bias.

Bennic, yes. Good quality caps.

Your plan sounds reasonable, especially seeing how tight money is right now. With good woofers and a crossover refresh, you'll enjoy the Heresy's. Later, if you are not interested in keeping them "original", I would recommend Claude's ported version of the Heresy. It's a woofer swap and you add an inexpensive port. Makes a big difference in the low-end output. Since I've said that, you will have everyone and their grandma chime in a say "just use a subwoofer" and you can do that too, but sometimes people don't want to use a sub or one is just not an option for whatever reason.

Good morning Henry - Sounds like this amp will be one for the books, no doubt. You'll be getting multiple offers for this one, I bet. Are you still going to use Orange Drop coupling caps in this build? Dayton (Parts Express) makes some film & foil coupling caps... they are super inexpensive, but seem to be high quality, about half the price of Orange Drops. Just FYI if you want to try some oneday. I've used them and I am happy with them.